To the Free Software Foundation, the cost of software is irrelevant. When
they selected the term free software, freedom, not money, was primarily
on their minds. The fact that English uses the same word to represent both
liberty and lack of cost was one of the reasons for the
creation of the open source movement. To avoid confusion, we’ll adopt the
Free Software Foundation’s convention of using gratis and
libre to refer to cost and freedom, respectively.

To an outsider, the free software movement and the open source movement may
resemble the "Judean Peoples’ Front" and the
"Peoples’ Front of Judea" (from the film Life of
Brian). The movements are remarkably similar in ideology, and most software
that is open source is also free software. The main difference is the level of
pragmatism in each camp:

The free software community believes that non-libre software is
antisocial—that a set of basic freedoms should accompany any software
license, and not including them harms the user’s basic rights. To this
end, they created the GNU General Public License (GPL). If you use code released
under the GPL as a basis for a larger work, the result must also be licensed
under the GPL. This concept is known as copyleft.

The open source community believes that the development model pioneered by
the increased collaboration generated by software-libre is superior to the
closed development model. To this end, leading members of the open source
community have been known to advocate a BSD-style license. The BSD license
imposes fewer restrictions than the GPL—it prevents you from claiming
credit for someone else’s work, but very little else. A company is free to
take BSD-licensed code and release a closed-source product based on it. To a
free software advocate, this plan is unacceptable; the creation of closed-source
software is antisocial and so should not be condoned or encouraged. To the open
source community, on the other hand, the original code is still available, and
products based on it will eventually be superior to the closed version, so in
the long term it makes little difference.

The ideology of the free software movement can be nice to watch from a
distance, but from a business perspective it’s of little relevance. What
is important is how these freedoms, or lack thereof, affect the bottom line. The
side-effect of software-libre—the fact that it’s also usually
gratis—can also affect this.

Support Costs

It is possible to "get the facts" from Microsoft and discover that
the total cost of ownership (TCO) of a Windows system is lower than that of a
similar Linux system. Microsoft, as the seller of Windows and the largest
developer of off-the-shelf closed-source software, can be relied on to be
completely objective on the matter of software-libre.

One of the major reasons Microsoft gives for the lower cost of Windows is the
lower support costs. In general, it’s cheaper to employ someone for a task
when a large number of people are able to fill the role. This is particularly
true of support. For most support roles, individuals are recruited with a basic
knowledge of the required software and gain experience on the job to fill more
advanced positions. The basic entry requirement is access to the platform for
home use—without this access, people getting onto the first tier are more
expensive, and this cost percolates though the entire hierarchy.

Currently, only a lucky few potential recruits have never used Microsoft
Windows. (Anyone who has never used Windows is lucky. The context here is
computer support roles, not Windows support, and managing to avoid using Windows
until the age when one would be applying for such a job is a case of extreme
good fortune.) In contrast, fewer people have used Linux or Macs, and even fewer
have used something like FreeBSD. The difference between Linux and Mac OS X here
is that it’s possible for an unemployed system administrator to download
and install Linux for free, and thus become more qualified for a junior Linux
administration position. If more Linux-admin jobs are available, this option
becomes more attractive. Thus, the inexpensiveness of Windows admins is a
self-perpetuating cycle that isn’t necessarily stable long-term.

The difference is more obvious when comparing something less ubiquitous than
an operating system. For a lot of small businesses, the software-libre database
PostgreSQL is a viable alternative to Oracle. The starting salary for an Oracle
administrator is higher, however, because very few people (legally) run Oracle
as the back-end database for personal projects.